Minimally invasive medical techniques have been used to reduce the amount of extraneous tissue which may be damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. Traditional forms of minimally invasive surgery include endoscopy. One of the more common forms of endoscopy is laparoscopy, which is minimally invasive inspection or surgery within the abdominal cavity. In traditional laparoscopic surgery, a patient's abdominal cavity is insufflated with gas, and cannula sleeves are passed through small (approximately ½-inch) incisions in the musculature of the patient's abdomen to provide entry ports through which laparoscopic surgical instruments can be passed in a sealed fashion.
The laparoscopic surgical instruments generally include a laparoscope for viewing the surgical field and surgical instruments having end effectors such as surgical tools. Typical surgical tools include clamps, graspers, scissors, staplers, and needle holders, for example. The surgical instruments are similar to those used in conventional (open) surgery, except that the end effector of each surgical instrument is separated from its handle by an approximately 12-inch long extension tube, for example, so as to permit the operator to introduce the end effector to the surgical site and to control movement of the end effector relative to the surgical site from outside a patient's body.
In order to provide improved control of the end effector, it may be desirable to control the surgical instrument with teleoperated actuators. The surgeon may operate controls on a console to indirectly manipulate the instrument that is connected to the teleoperated actuators. The surgical instrument is detachably coupled to the teleoperated actuators so that the surgical instrument can be separately sterilized and selected for use as needed instrument for the surgical procedure to be performed. The surgical instrument may be changed during the course of a surgery.
Performing surgery with teleoperated surgical instruments creates new challenges. One challenge is the need to maintain the region adjacent the patient in a sterile condition. However, the motors, sensors, encoders and electrical connections that are necessary to control the surgical instruments typically cannot be sterilized using conventional methods, e.g., steam, heat and pressure or chemicals, because they would be damaged or destroyed in the sterilization process.
Another challenge with teleoperated surgery systems is that a surgeon will typically employ several different surgical instruments during a procedure. A number of different surgical instruments will typically be introduced through the same trocar sleeve during the operation to limit the number of incisions required. Thus, there are a limited number of instrument manipulators available, often fewer than the number of surgical instruments used during a procedure. Therefore the surgical instruments may be attached and detached from the same instrument holder a number of times during an operation.
It would be desirable to provide an easier and more effective way to engage a surgical instrument with a teleoperated actuator drive while preventing contamination of the teleoperated actuator and allowing quick and reliable engagement of the mechanical couplers that transfer motion from the teleoperated actuator drive to the surgical instrument through a sterile barrier.